System and method for facilitating hemostasis of blood vessel punctures with absorbable sponge

ABSTRACT

A method of superhydrating an absorbable sponge for delivery to a body to facilitate hemostasis includes the step of subjecting the absorbable sponge to a high pressure fluid to hydrate the absorbable sponge. According to one method, a dry piece of absorbable sponge is placed in a delivery device. The absorbable sponge is then subjected to a high pressure fluid by injecting fluid into the delivery device to rapidly and completely hydrate the absorbable sponge in the delivery device. The high pressure fluid used for rapidly and completely hydrating the absorbable sponge is delivered at a pressure of about 5 psi or greater. The hydrated absorbable sponge may be delivered to a puncture site in a blood vessel to facilitate hemostasis of the puncture site.

This application is a continuation-in-part of U.S. Ser. No. 09/071,284filed May 1, 1998, which is incorporated herein by reference in its nowU.S. Pat. No. 6,162,192.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention relates to a closure system for blood vessel punctures,and more particularly, the invention relates to a system and method forfacilitating hemostasis of blood vessel punctures with an absorbablesponge material.

2. Brief Description of the Related Art

A large number of diagnostic and interventional procedures involve thepercutaneous introduction of instrumentation into a vein or artery. Forexample, coronary angioplasty, angiography, atherectomy, stenting ofarteries, and many other procedures often involve accessing thevasculature through a catheter placed in the femoral artery or otherblood vessel. Once the procedure is completed and the catheter or otherinstrumentation is removed, bleeding from the punctured artery must becontrolled.

Traditionally, external pressure is applied to the skin entry site tostem bleeding from a puncture wound in a blood vessel. Pressure iscontinued until hemostasis has occurred at the puncture site. In someinstances, pressure must be applied for a up to an hour or more duringwhich time the patient is uncomfortably immobilized. In addition, a riskof hematoma exists since bleeding from the vessel may continue beneaththe skin until sufficient clotting effects hemostasis. Further, externalpressure to close the vascular puncture site works best when the vesselis close to the skin surface and may be unsuitable for patients withsubstantial amounts of subcutaneous adipose tissue since the skinsurface may be a considerable distance from the vascular puncture site.

More recently, devices have been proposed to promote hemostasis directlyat a site of a vascular puncture. One class of such puncture sealingdevices features an intraluminal anchor which is placed within the bloodvessel and seals against an inside surface of the vessel puncture. Theintraluminal plug may be used in combination with a sealing materialpositioned on the outside of the blood vessel, such as collagen. Sealingdevices of this type are disclosed in U.S. Pat. Nos. 4,852,568;4,890,612; 5,021,059; and 5,061,274.

Another approach to subcutaneous blood vessel puncture closure involvesthe delivery of non-absorbable tissue adhesives, such cyanoacrylate, tothe perforation site. Such a system is disclosed in U.S. Pat. No.5,383,899.

The application of an absorbable material such as collagen or anon-absorbable tissue adhesive at the puncture site has severaldrawbacks including: 1) possible injection of the material into theblood vessel causing thrombosis; 2) a lack of pressure directly on theblood vessel puncture which may allow blood to escape beneath thematerial plug into the surrounding tissue; and 3) the inability toaccurately place the absorbable material plug directly over the puncturesite.

The use of an anchor and plug system addresses these problems to someextent but provides other problems including: 1) complex and difficultapplication; 2) partial occlusion of the blood vessel by the anchor whenplaced properly; and 3) complete blockage of the blood vessel or abranch of the blood vessel by the anchor if placed improperly. Anotherproblem with the anchor and plug system involves reaccess. Reaccess of aparticular blood vessel site sealed with an anchor and plug system isnot possible until the anchor has been completely absorbed because theanchor could be dislodged into the blood stream by an attempt toreaccess.

Yet another approach to subcutaneous puncture closure involves theinternal suturing of the blood vessel puncture with a specially designedsuturing device. However, these suturing devices involve a significantnumber of steps to perform suturing and require substantial expertise.

Accordingly, it would be desirable to provide a system for facilitatinghemostasis of blood vessel punctures which addresses the drawbacks ofthe known systems.

SUMMARY OF THE INVENTION

One aspect of the present invention relates to a device for facilitatinghemostasis of a puncture in the wall of a blood vessel including anintroducer for compressing a sponge pledget for delivery into a patientto seal the puncture, the introducer including a staging chamber with afirst diameter configured to receive the absorbable sponge pledget, adelivery chamber with a second diameter smaller than the first diameter,and a tapered section between the staging chamber and the deliverychamber for compressing the pledget, and a plunger insertable into theintroducer for ejection of the pledget from the delivery chamber into apatient to seal the puncture in the blood vessel wall.

In accordance with another aspect of the present invention, a method forfacilitating hemostasis of a puncture in the wall of a blood vesselincludes the steps of establishing a depth of a blood vessel puncture ofa patient; loading an introducer with a sponge pledget by hydrating andcompressing the pledget; loading the introducer over a guidewirepositioned in the blood vessel by inserting the guidewire through thehydrated and compressed pledget; and ejecting the pledget adjacent theblood vessel puncture to facilitate hemostasis while maintaining theguidewire in place.

In accordance with an additional aspect of the present invention, adevice for facilitating hemostasis of a puncture in the wall of a bloodvessel includes a staging chamber for hydrating a sponge pledget inpreparation for delivery of the pledget into a patient to seal thepuncture, a delivery chamber for delivering the hydrated sponge pledgetto the puncture, and a plunger insertable into the delivery chamber forejection of the pledget from the delivery chamber into a patient to sealthe puncture in the blood vessel wall. A distal end of the stagingchamber having a tapered lumen and a proximal end of the deliverychamber connectable to the distal end of the staging chamber fordelivery of the pledget from the staging chamber to the deliverychamber.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will now be described in greater detail with reference tothe preferred embodiments illustrated in the accompanying drawings, inwhich like elements bear like reference numerals, and wherein:

FIG. 1 is a top view of a blood vessel puncture sealing kit;

FIG. 2 is a side cross sectional view of a punctured blood vessel and atract dilator for locating the puncture;

FIG. 3 is a side view of an introducer and pledget prior to placementwithin the introducer;

FIG. 4 is a side view of an introducer having a pledget positionedwithin the introducer staging chamber and a syringe attached to theintroducer;

FIG. 5 is a side view of the introducer and syringe with the pledgethydrated and advanced to a delivery chamber within the introducer;

FIG. 6 is a side cross sectional view of a punctured blood vessel withthe introducer and plunger positioned for delivery of the pledget;

FIG. 7 is a side cross sectional view of a punctured blood vessel withthe pledget being deposited at the puncture site;

FIG. 8 is a side cross sectional view of a punctured blood vessel with ahydrated and kneaded pledget deposited at the puncture site, theguidewire removed, and the delivery system being withdrawn;

FIG. 9 is a side cross sectional view of a punctured blood vessel with ahydrated and kneaded pledget facilitating hemostasis of the puncturesite;

FIG. 10 is a side cross sectional view of an alternative embodiment ofan introducer;

FIG. 11 is a cross sectional view of a distal end of an introduceraccording to another alternative embodiment having a central channel forreceiving the guidewire;

FIG. 12 is a cross sectional side view of a distal end of an introducerwith a connector for connecting a syringe;

FIG. 13 is a bottom view of a template for use in forming a pledget;

FIG. 14 is a side view of the template of FIG. 13;

FIG. 15 is a top view of the template of FIG. 13 as it is placed forcutting a piece of a sponge sheet for formation of the pledget;

FIG. 16 is a bottom view of an alternative embodiment of a template foruse in forming a pledget;

FIG. 17 is a side view of the template of FIG. 16;

FIG. 18 is a top view of the template of FIG. 16 as it is placed forcutting a piece from a sponge sheet for formation of the pledget;

FIG. 19 is a bottom view of an alternative embodiment of a templatehaving creasing ribs;

FIG. 20 is an end view of the template of FIG. 19;

FIG. 21 is a side cross sectional view of a vent cap;

FIG. 22 is a side cross sectional view of the vent cap of FIG. 21positioned on the distal end of a delivery chamber;

FIG. 23 is a side cross sectional view of an alternative embodiment of avent cap;

FIG. 24 is a side cross sectional view of the vent cap of FIG. 23positioned on a staging chamber;

FIG. 25 is a side view of a pusher for use in the present inventionhaving a proximal stop and a sliding luer;

FIG. 26 is a side cross sectional view of the distal end of a pusherhaving a funnel shaped distal lumen;

FIG. 27 is a side view partially in cross section of an introducer withthe pusher of FIG. 25;

FIG. 28a is a side cross sectional view of an introducer with a pusherhaving a rachet system; FIG. 28b is an enlarged view of the detail B ofFIG. 28a showing the ratchet teeth and tab; FIG. 28c is a side crosssectional view of an introducer with a detent; FIGS. 28d-f are sideviews of pushers for use with the introducer of FIG. 28c;

FIG. 29 is a top view of a pledget delivery system including a two pieceintroducer with separate staging and delivery chambers;

FIG. 30 is a side view of the assembled introducer of FIG. 29 fordelivery of the pledget from a staging chamber to the delivery chamber;

FIG. 31 is a side view of the delivery chamber with the pusher connectedto the delivery chamber for delivery of the pledget;

FIG. 32 is a side view of the delivery chamber and pusher after deliveryof the pledget;

FIG. 33 is a side view of a distal end of the dilator having a distalprotrusion for strain relief;

FIG. 34 is a side view of a distal end of a dilator having a distallumen providing a strain relief feature;

FIG. 35 is a side cross sectional view of a pledget with a rapidlydissolvable tip;

FIG. 36 is a side cross sectional view of a punctured blood vessel withthe pledget of FIG. 35 being deposited;

FIG. 37 is a schematic side view of a system for delivering a pledgetthrough a sheath; and

FIG. 38 is a schematic side view of an alternative system for deliveringa pledget through a sheath.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

An over the wire delivery system delivers an absorbable sponge pledgetin a hydrated condition to a blood vessel puncture site to achievehemostasis. One embodiment of the over the wire delivery system includesa tract dilator 10, an introducer 12, and a pusher 14, illustrated inkit form in FIG. 1. The system allows over the wire delivery of theabsorbable sponge material directly to the puncture site to achievehemostasis. Over the wire delivery ensures that the sponge material isproperly positioned to fully occlude the puncture. In addition, theabsorbable sponge material is delivered in a hydrated state whichimmediately expands to stop blood flow through the puncture. Theintroducer allows the delivery of more absorbable sponge materialthrough a smaller tract by hydrating and compressing the absorbablesponge material.

Prior to discussing the present invention in further detail, thefollowing terms are defined:

“Pledget” means a piece of sponge formed into a generally elongatedshape having a size which allows delivery in a hydrated state through adelivery cannula or introducer to a site of a puncture in a bloodvessel.

“Sponge” means a biocompatible material which is capable of beinghydrated and is resiliently compressible in a hydrated state.Preferably, the sponge is non-immunogenic and may be absorbable ornon-absorbable.

“Absorbable sponge” means sponge which when implanted within a human orother mammalian body is absorbed by the body.

“Hydrate” means to partially or fully saturate with a fluid, such as,saline, water, contrast agent, thrombin, therapeutic agents, or thelike.

“Kneading” of the absorbable sponge material means both dry and wetmanipulation of sponge material which compresses, enlarges, or changesthe shape of the sponge material causing the sponge material to haveimproved expansion response.

As shown in FIG. 1, the tract dilator 10, the introducer 12, and thepusher 14 may be provided to a medical facility in the form of a kit orindividually. The tract dilator 10 as illustrated in FIGS. 1 and 2includes a distal tip 20, a proximal end 22, and a lumen 24 extendingfrom the distal tip to the proximal end of the tract dilator. The lumen24 is provided to allow the tract dilator 10 to be received over aguidewire 26 which extends through the puncture wound 100 into the bloodvessel 102. The tract dilator 10 may have a constant cross section ormay taper slightly to a smaller diameter at the distal tip 20. Accordingto an alternative embodiment, the tract dilator 10 may have a narrowshaft with an enlarged distal tip. The distal tip 20 has rounded edgesto prevent catching on subcutaneous tissue 104 as the tract dilator 10is inserted through the skin 106 and tissue to the blood vessel puncturesite. The tract dilator distal tip 20 has a diameter such that the tipof the tract dilator will not pass into the blood vessel but will stopand provide tactile feedback when it reaches the external blood vesselwall 102. Other embodiments of tract dilators will be discussed belowwith respect to FIGS. 33 and 34.

A depth indicator 30 is positioned around the tract dilator 10 and ismovable in an axial direction. Once the tract dilator 10 has beeninserted until the distal tip 20 abuts the external wall of the bloodvessel 102, as shown in FIG. 2, the depth indicator 30 is manuallypositioned adjacent the patient's skin 106. Alternatively, the depthindicator 30 can be pushed to a depth indicating position by the skin106 as the dilator is inserted. Preferably, the depth indicator 30 is anelastic ring which is movable axially on the tract dilator 10 andmaintains a measured position for comparison with the introducer 12.

A side view of an introducer 12 is illustrated in FIGS. 1 and 3. Theintroducer 12 includes a staging chamber 34 for receiving an absorbablesponge pledget 40 and a delivery chamber 36 for receipt of a hydratedand compressed pledget from the staging chamber. A tapered section 38 isprovided between the staging chamber 34 having a larger diameter lumenand the delivery chamber 36 having a smaller diameter lumen. The taperedsection 38 of the introducer 12 acts as a compression member to compressthe hydrated pledget 40 into the delivery chamber. The introducer 12also includes a luer fitting 42 at a proximal end for connection to aconventional syringe and wing members 44 for use in grasping theintroducer. A two part introducer having separate delivery and stagingchambers will be discussed below with respect to FIGS. 29-31.

The absorbable sponge pledget 40 according to one preferred embodimentof the invention is formed from a sheet of absorbable sponge materialwhich has been cut into a rectangular shape and rolled to form acompact, substantially cylindrical, elongated pledget. The pledget 40 issized to be received within the staging chamber 34 of the introducer 12in a dry rolled state. Templates for use in forming the pledget 40 areshown in FIGS. 13-20.

Once the pledget 40 has been inserted into the staging chamber 34 of theintroducer 12, a conventional syringe 50 containing a hydrating fluid isconnected to the luer fitting 42, as shown in FIG. 4. The pledget 40 isthen hydrated within the staging chamber 34 by injecting a fluid intothe staging chamber from the syringe 50 causing the pledget to swell,partially or fully blocking the lumen of the introducer. The partialhydration or wetting of the exterior surface of the pledget 40 creates alubricous surface on the pledget. The hydrated pledget 40 is then forcedinto the delivery chamber 36 by injecting additional fluid with thesyringe 50 to force the pledget through the tapered section 38 to thedelivery chamber 36. For a somewhat smaller pledget 40 which does notentirely block the lumen of the introducer 12 after hydrating, theventuri effect will help to draw the pledget into the delivery chamber36.

As shown in FIG. 5, a finger may be placed over the distal end of theintroducer 12 during delivery of the pledget 40 to the delivery chamber36 to prevent the pledget from being ejected from the introducer by thepressure of the fluid. Preferably, one or more vent holes 46 areprovided in the side walls of the introducer adjacent the distal tip toallow air and liquid to escape from the introducer while the pledget 40is positioned for delivery. These vent holes 46 are small enough toprevent the pledget 40 from passing substantially into the vent holes.

As an alternative to placement of a finger at the distal end of theintroducer 12 during advancement of the pledget 40 into the deliverychamber, a removable vent cap may be used as described below withrespect to FIGS. 21-24. Further, the vent holes 46 may be omitted and ascreen or a cap having a screen may be used to allow fluid to passthrough the screen while the screen prevents the pledget 40 from beingejected.

Another alternative method for positioning the pledget adjacent thedistal end of the delivery chamber is to provide a proximal vent hole inthe side wall of the delivery chamber. The proximal vent hole ispositioned such that when the pledget has moved to the distal end of thedelivery chamber, the pledget is substantially clear of the proximalvent allowing additional injected fluid to pass out of the deliverychamber through the vent. According to this method, the proximal ventacts as a fluid release valve to prevent further advancement of thepledget once the pledget has reached a desired position.

The introducer 12 also includes a depth indicator 52 which is an axiallymovable member used to indicate the depth to which the introducer shouldbe inserted into the patient to achieve the proper positioning of thepledget 40 at the puncture site. The depth indicator 52 of theintroducer 12 is aligned with the depth indicator 30 on the tractdilator 10 to achieve proper pledget delivery positioning.

The introducer 12 may be formed in any known manner such as by injectionmolding from a plastic material. Preferably, the introducer 12 istransparent so that the pledget 40 can be viewed through the introducerand the user can visually confirm the pledget position. The introducerlumen may be provided with a friction reducing coating for improvedpledget delivery. The delivery fluid also reduces friction for improveddelivery by wetting the exterior surface of the pledget.

The pusher 14, as illustrated in FIG. 1, includes a distal end 56 whichis configured to slide within the lumen of the delivery chamber 36 ofthe introducer 12. Preferably, there is a very small clearance or aresilient interference between the outer diameter at the distal end 56of the pusher 14 and the inner diameter of the delivery chamber 36 toprevent portions of the pledget from getting caught between the pusherand the introducer 12. A resilient pusher distal end 56 or a sealingmember on the pusher 14 may be used to accomplish or approach aresilient fit between the introducer 12 and the pusher.

The pusher 14 also may include a fitting 58 for connecting the proximalend of the pusher to the proximal end of the introducer 12. The fitting58 acts as a stop to limit the motion of the pusher 14 with respect tothe introducer 12. When the pusher 14 is locked to the introducer 12,the two may be used together to apply localized compression to thepuncture site. A female luer fitting 60 may also be included at theproximal end of the pusher 14 for connection of a syringe to the pusherfor injection of beneficial agent through the pusher.

One method of delivering an absorbable sponge pledget 40 to facilitatehemostasis of a blood vessel puncture wound will now be described withrespect to the steps illustrated in FIGS. 2-9. After an intravascularprocedure has been completed, a guidewire 26 is already in place passingthrough the subcutaneous tissue into the blood vessel. Alternatively, ifa guidewire is not already in place the guidewire is inserted through anaccess sheath used in the intravascular procedure and the access sheathis then removed. The guidewire 26 is maintained in place with a proximalend extending from the patient's body and a distal end extending throughthe skin 106 and subcutaneous tissue 104, through the blood vesselpuncture 100, and into the blood vessel 102. As discussed above, thetract dilator 10 is threaded over the guidewire 26 and advanced downthrough the subcutaneous tissue 104 to an outside surface of the bloodvessel 102. Resistance is felt when the tract dilator distal tip 20contacts the exterior of the blood vessel and the tract dilator will noteasily pass though the vessel puncture 100 and into the vessel. Thedepth indicator 30 on the tract dilator 10 is moved to abut the skinsurface 106 indicating a distance from the skin surface to the bloodvessel puncture site. The tract dilator 10 is then removed over theguidewire 26 and the introducer depth indicator 52 is aligned with thetract dilator depth indicator 30.

A sheet of absorbable sponge material is cut into a rectangle, is rolledtightly to form a pledget 40, and is placed into the staging chamber 34of the introducer 12. The steps of cutting and rolling the pledget 40and placing the dry pledget in the introducer staging chamber 34 may beperformed before or after the intervascular procedure. Alternatively,the introducer 12 may be provided preloaded with a prepared pledget 40.With the pledget 40 placed in the introducer, the syringe 50 is filledwith a hydrating fluid such as saline, thrombin, contrast agent, othertherapeutic agent, or the like and attached to the introducer 12 asillustrated in FIG. 4. Fluid is injected slowly into the introducer 12to hydrate the pledget 40. The user then pauses to allow hydration andinitial swelling of the pledget 40. Sufficient hydration may occur inabout 20 to 30 seconds or less depending on the size of the pledget 40.

As shown in FIG. 5, the user then places a finger over the distal end ofthe introducer 12 and injects fluid with the syringe 50 to force thepledget 40 through the tapered section 38 and into the smaller end ordelivery chamber 36 of the introducer 12. Injection of fluid is stoppedwhen the pledget 40 is positioned at the distal end of the deliverychamber 36. At this point the syringe 50 is removed and the introduceris loaded over the proximal end of the guidewire 26 for the delivery ofthe pledget 40 to the puncture site.

As shown in FIG. 6, a proximal end of the guidewire 26 is fed into thedistal end of the introducer 12 though the hydrated and compressedpledget 40 and out the proximal end of the introducer. Preferably, theguidewire 26 is fed through substantially the center of the pledget 40to ensure that the implanted pledget is centered over the blood vesselpuncture 100. Alternatively, the guidewire may be inserted along a sideof the pledget 40, through a separate second lumen of the introducer,through an axial lumen in the pledget, or through a low density centerof the pledget.

After feeding the guidewire 26 through the introducer, the guidewire 26is fed through the pusher 14 and the pusher is advanced into theintroducer until the distal end 56 of the pusher is in contact with thepledget 40. The introducer 12 and pusher 14 are then advanced togetherdown though the skin 106 and the subcutaneous tissue 104 until the depthindicator 52 on the exterior of the introducer is at the skin level.

In the step illustrated in FIG. 7, the pusher 14 is held stationarywhile the introducer 12 is withdrawn proximally preferably to a distanceof about 75% of the length of the compressed, hydrated pledget 40. This75% withdrawal distance may be indicated with an appropriate marker onthe introducer 12 or the plunger 14 or by contact between the fittings42, 58 of the introducer and plunger. The portion of the pledget 40ejected into the tissue quickly expands upon delivery to fill theavailable space and provide localized compression. With the pusher 14and introducer 12 in the position illustrated in FIG. 7 and the pledget40 partially ejected, a slight forward pressure is maintained by theoperator on the introducer and pusher to increase local compression fora period of time of approximately 1 minute to allow hemostasis to begin.The forward pressure causes the pledget 40 to be compressed around thepuncture site, as shown in FIG. 7. The guidewire 26 is then completelyremoved from the introducer 12 and the pusher 14. The introducer 12 iswithdrawn the remaining approximately 25% by engaging the fitting 58 ofthe pusher with the female luer fitting 42 of the introducer tocompletely discharge the pledget 40 into the subcutaneous tissue 104above the puncture site 100. A slight forward pressure can then bemaintained by the operator on the introducer 12 and pusher 14 forapproximately 1 minute before the introducer and pusher are removed fromthe tissue tract leaving the absorbable sponge pledget 40 positionedagainst the outer vessel wall, as shown in FIG. 9, providing localcompression and facilitating hemostasis. The delivered pledget 40maintains hemostasis until healing of the blood vessel 102 occurs. Thepledget 40 is absorbed by the body over time.

One type of absorbable sponge material which is acceptable for use inthe present invention is Gelfoam, manufactured by the Upjohn Company.Gelfoam is a porous, pliable, cross-linked gelatin material and isavailable commercially in sheet form as pre-compressed or non-compressedsponge. The material may be provided preformed as a pledget 40 or may becut with a punch, or a stencil or template and knife and rolled to forma pledget as described above. Once hydrated, the pledget 40 can beeasily compressed to fit into a lumen having a smaller cross sectionalarea than the original cross sectional area of the pledget.Additionally, the kneading of the hydrated pledget 40 during deliveryencourages air trapped within the Gelfoam to be expelled and replacedwith fluid, allowing rapid expansion upon delivery. When a pledget 40 ofa pre-compressed Gelfoam is hydrated and kneaded (expelling air) duringdelivery, the pledget will have the absorption capacity to rapidlyexpand to many times (e.g., 3 or more times) its original dry volumeupon delivery. When a pledget 40 of the non-compressed Gelfoam ishydrated and kneaded (expelling air) during delivery, the pledget willhave the absorption capacity to rapidly expand to its original dryvolume upon delivery. These properties make the Gelfoam sponge materialparticularly useful for facilitating hemostasis of puncture wounds byinjection.

Abrupt lumen diameter changes within the introducer 12, such as at thetapered section 38, will improve “kneading” of the absorbable spongematerial passing through the introducer. Manipulation of the dryabsorbable sponge material, such as the rolling of the pledget 40, alsoprovides kneading. Kneading improves hydration of the sponge materialthereby improving the expansion properties of the hydrated deliveredabsorbable sponge.

According to alternative embodiments of the introducer, enlarged,recessed, or irregular areas in the lumen of the introducer are providedto impart additional kneading action to the absorbable sponge materialfurther improving expansion properties of the sponge. FIG. 10illustrates one such alternative embodiment of the introducer 12 a inwhich the delivery chamber of the introducer is provided with twoenlarged areas 64. As the absorbable sponge pledget 40 passes throughthe enlarged areas 64 of the introducer 12 a, the material expands andis compressed by the introducer to increase kneading of the pledget.According to another alternative embodiment, the introducer may beprovided with a plurality of staggered irregularities for improvedkneading of the absorbable sponge pledget 40. The irregularities,enlargements, or recesses will preferably have a relatively smoothsurface to prevent the absorbable sponge material from becoming caughtas it passes through the introducer. Preferably, a length “l” between adistal end of the introducer 12 and the distal most of theirregularities, enlargements, or recesses is sufficient to accommodatethe entire hydrated, compressed pledget such that the pledget 40 willnot become trapped between the plunger and the enlargements.

Another alternative embodiment for improved kneading of the pledget 40includes features on the guidewire, such as, irregularities, curves,bends, or the like. The guidewire kneading features will improvekneading of the pledget 40 as the guidewire 26 is inserted through thepledget.

In addition to kneading, pledget delivery is enhanced by super hydrationor rapid hydration of the pledget at high pressure. Rapid hydration maybe accomplished by high pressure injection of a fluid into theintroducer 12 while placing a finger or vent cap over the distal end ofthe introducer. Super hydration can also be achieved by placing theintroducer 12, with the pledget 40 inside, into a pressurized containerof fluid. Preferably, fluid pressures of 5 psi or greater are used forsuper hydration of the sponge material. This super hydration providesrapid and complete hydration of the material in preparation for use.

The embodiment of FIG. 10 also includes a delivery chamber 36 a providedwith internal barbs 66 which help to retain the compressed pledget 40positioned adjacent the distal end of the introducer 12 a while theguidewire 26 is inserted through the pledget material. The internalbarbs 66 are small enough to not cause interference with the passage ofthe pusher. The barbs 66 help to hold the pledget 40 in place as theguidewire 26 is inserted through the pledget. In addition to or in placeof the internal barbs 66, other features may be used, such as ribs, atextured surface, holes, or the like. One example of an alternativestructure for retaining the pledget 40 at the distal end of theintroducer 12 a during insertion of the guidewire is a distalcounterbore (not shown). The counterbore may be formed by cutting a borein from the distal end of the introducer 12 a which is coaxial with theintroducer lumen and has a diameter which is slightly larger than thediameter of the introducer lumen. The counterbore may have a lengthwhich is approximately the length of the pledget 40 or smaller.Preferably, the length of the counterbore is approximately ⅔ to ½ thelength of the pledget 40.

The barbs 66, counterbore, and other retention features are particularlyuseful when using a conventional coiled guidewire which creates asignificant amount of friction when threaded through the absorbablesponge material. Alternatively, a smooth, solid shaft guidewire, aplastic sheathed guidewire, or a hydrophilically coated guidewire can beused. These smooth guidewires are more easily threaded through theabsorbable sponge material. A guidewire with a reduced diameter proximalportion will also facilitate threading of the guidewire 26 through thepledget 40.

As an alternative to the barbs 66 or a specially designed guidewire, theplunger 14 can be used to hold the pledget 40 in place during threadingof the guidewire 26 through the pledget. A hydraulic back pressure canalso be created to hold the pledget 40 in place by blocking the proximalend of the introducer 12, such as by the user's finger. Such a hydraulicback pressure will help to hold the pledget in place in the deliverychamber.

Although the use of a tract dilator 10 has been described above, theintroducer 12 can be used in place of the dilator and the depthdetermining step can be performed while inserting the introducer,particularly where a plastic sheathed guidewire, other friction reducingguidewire, or other friction reducing feature is used. The use of theintroducer 12 as the dilator eliminates errors which may occur inaccurately setting the depth indicator 52 on the introducer.

According to one embodiment of the invention, the pusher 14 is insertedwithin the introducer 12 and the luer fitting 58 at the proximal end ofthe pusher is attached to the luer fitting 42 on the introducer. Thisintroducer/pusher system is advanced over a guidewire into the tissuetract to establish the location of the exterior wall of the bloodvessel. The exterior wall of the blood vessel is palpitated with theintroducer/pusher system and the depth indicator 52 on the introducer isset at the skin level.

According to an alternative embodiment, an introducer/pusher system maybe used for dilation in which the pusher 14 or obturator used duringdilation is different from the pusher which is used for delivery of thepledget. The pusher 14 for use during dilation preferably has a luerlock at a proximal end which locks to the proximal end of the introducer12 and has a length such that the distal ends of the pusher andintroducer are aligned. After setting of the depth indicator 52, thesystem is then removed from the tissue tract and the pusher 14 isremoved from the introducer 12. The introducer 12 is then prepared fordelivery of the pledget 40 by hydrating and staging the pledget withinthe introducer. The introducer 12 is then reintroduced over theguidewire and advanced into the tissue tract to the depth indicated bythe depth indicator 52. In this manner, reliable, accurate, andrepeatable placement of the pledget 40 is performed without the use of aseparate tract dilator.

According to another embodiment of the invention, the introducer isinserted to the pledget delivery site through a sheath. In this method,the sheath with a removable dilator positioned inside the sheath isadvanced over the guidewire into a tissue tract to establish thelocation of an arterial puncture site. Once the exterior wall of thevessel has been located by palpating, the dilator is withdrawn leavingthe sheath in place. The introducer 12 with prepared pledget 40 andpusher 14 are then inserted into the sheath over the guidewire. Theintroducer 12 may be locked to the sheath, such as by a luer lock. Thiswill position the distal end of the introducer 12 at the distal end ofthe sheath in preparation for pledget delivery. The combined sheath andintroducer system is used to deposit the pledget in the manner describedabove.

Alternatively, a sheath such as the sheath which was used during theprocedure may be used for delivery of the pledget. For delivery of thepledget through the sheath, the sheath is first positioned adjacent theexterior of the blood vessel either by palpating with the sheath and aninternal dilator or by any of the known visualization methods such asfluoroscopy. The sheath may be preloaded with the pledget or the pledgetmay be loaded after sheath positioning. The pledget is delivered byinserting a plunger into the sheath and withdrawing the sheath over theplunger to deposit the pledget adjacent the exterior of the bloodvessel.

For preloading the sheath with the pledget, a staging chamber isattached to the proximal end of the sheath and the pledget is advancedby fluid injection to the distal end of the sheath. The pledget may bepositioned properly by use of a distal vent or vent cap which allowsexcess fluid to escape as discussed above. Alternatively, a proximalvent may be provided in the sheath at a location which corresponds to aproximal end of the pledget when the pledget is positioned at a distalend of the sheath. Once the pledget has been advanced so the proximalend of the pledget is at or past the proximal vent, the fluid will exitthrough the vent in the side of the sheath preventing furtheradvancement of the pledget. The sheath with the pledget loaded at thedistal end is then inserted over the guidewire to the puncture site anda plunger is used to deploy the pledget.

When the sheath is used for delivery of the pledget without firstremoving the sheath from the tissue tract, the sheath is withdrawn untila distal tip of the sheath is adjacent the outer vessel wall. This canbe determined by known visualization techniques. The staging chamber isthen attached to the proximal end of the sheath and used to hydrate andadvance the pledget to the distal end of the sheath. The pledget may beadvanced through the sheath around or beside the guidewire.Alternatively, the guidewire may be removed before the pledget isconveyed into the sheath. A proximal vent, as described above, ispreferably used to position the pledget at the distal end of the sheath.The pledget is then delivered with the plunger.

A sheath 208 can also be used for delivery of the pledget 40 withoutfirst removing the sheath from the vessel, as shown in the embodimentsin FIGS. 37 and 38. In this way, the sheath 208 maintains hemostasis atthe vessel puncture site 210 while the distal end of the pledget 40 ispositioned at a depth corresponding to the outer surface of the vesselwall 212.

As shown in FIG. 37, the pledget 40 can be placed directly into thesheath 208 such as by use of an introducer or staging chamber.Preferably, a proximal vent 214 is provided in the sheath 208 toposition the pledget at a proper position within the sheath. The pledget40 is delivered to the sheath and the proximal end of the pledget ispositioned at a depth corresponding to the outer wall of the vessel 212.The proper positioning of the sheath and the pledget is achieved bylocating an imaging marker 216 on the sheath at an outer wall of thevessel 212. The pusher 14 is then used to hold the pledget 40 stationarywith respect to the vessel while the sheath 208 is withdrawn from thepuncture site 210.

FIG. 38 illustrates an alternative embodiment of a sheath deliverysystem in which an introducer 12 is used to deliver a pledget 40 intothe sheath 208. As in the embodiment of FIG. 37, the sheath 208 ismaintained in the puncture site 210 during delivery of the pledget intothe sheath. The introducer 12 may be inserted into the sheath 208 andsecured to the sheath in a known manner such that the distal end of thepledget 40 is positioned at a depth corresponding to the outer surfaceof the vessel wall 212. The proper positioning may be determined byimaging a marker on the sheath 208 that corresponds to the distal end ofthe introducer 12. Alternatively, positioning can be determined byimaging either the introducer 12 or the pledget 40 if these elements areformed of an imaginable material. The plunger 14 is then used to holdthe pledget 40 in position with respect to the vessel wall 212 while thesheath 208 and introducer 12 are withdrawn from the puncture site.

According to the embodiments of FIGS. 37 and 38, the sheath 208maintains hemostasis of the puncture site 210 until a distal tip of thesheath has exited the puncture site. When the sheath exits the puncturesite, the pledget 40 is exposed and begins to provide hemostasis. Whenthe entire sheath 208 has been withdrawn the pledget is left within thetissue tract and provides continued hemostasis.

FIG. 11 illustrates a cross section of a distal end of an introducer 12b according to an alternative embodiment of the invention in which acentral lumen 70 is provided within the introducer for receiving theguidewire 26. The central lumen 70 allows the guidewire to be insertedeasily through the pledget 40. According to this embodiment the centrallumen 70 is formed by a tube 72 which preferably extends at least thelength of the hydrated pledget 40 when the pledget is positioned withinthe delivery chamber 36 b. The tube 72 is supported by one or more ribs74 connected to the exterior of the tube and to the interior wall of theintroducer 12 b. The pledget 40 for use with this embodiment is eitherformed with a generally U-shaped cross section to be accommodated in theU-shaped cross section of the delivery chamber 36 b or deforms duringloading to surround the one or more ribs 74 and tube 72.

FIG. 12 shows a proximal end of an introducer 12 connected to aspecially designed connector 80 for connecting the introducer to thesyringe 50. The connector 80 is used when the proximal end of theintroducer 12 is larger in diameter than the standard syringe fitting.The connector 80 includes a first end 82 for connection to the syringe50 and a second end 84 for connection to the introducer 12. In use, theconnector 80 is removed from the introducer 12. The pledget 40 is theninserted into the introducer 12 and the connector 80 is reattached. Thesyringe 50 is then connected to the connector 80 for injection of fluidinto the introducer 12 to hydrate, advance, and compress the pledget 40.

FIGS. 13-20 illustrate three different embodiments of templates for usein cutting a piece of a desired size from a sheet of sponge to form thepledget 40. FIG. 13 illustrates a template 108 having a rectangularshaped recess 110 with edges of the recess forming edge guides 112, 114.As shown in FIG. 15, the edge guides 112, 114 of the recess 110 areplaced against the edges of a sheet 116 of sponge material. The template108 is pressed downward and the sponge sheet is cut along two edges 118,120 of the template 108.

An alternative embodiment of a template 124 is illustrated in FIG.16-18. The template 124 includes a recess 126 with a single edge guide127 and two pressure rails 128. The pressure rails 128 help to securelyhold the template 124 on the sponge sheet 116 during cutting alongcutting edges 130, 132 of the template. Although the templates of FIGS.13 and 16 are illustrated with two cutting edges, it should beunderstood that the templates according to the present invention mayinclude one or more cutting edges depending on the size and shape of thesheet 116 from which the piece of sponge material is to be cut. Inaddition, the templates may be provided with up to three edge guides112, 114, 127. The templates are provided with recesses for ease ofalignment of the templates with the sheet of sponge material. However,alignment may alternatively be provided by use of transparent templateswith edge markings or by alignment with the edges of the templatethemselves. For example, the template may be formed of the same size asthe sponge piece to be cut without any recess or edge guides.

FIGS. 19 and 20 show an alternative embodiment of a template 136 havinga recess 138 and creasing ridges 140. The creasing ridges or ribs 140will create creases in the sponge material to assist in folding orrolling of the pledget 40. Any number of creasing ridges 140 may be useddepending on the configuration of the pledget to be formed. For example,creasing ridges 140 may be formed at evenly spaced intervals across theentire template surface. The creasing ridges 140 are preferably about0.2 to 1.5 mm wide and about 0.5 to 2 mm high with a spacing of about0.5 to 5 mm. The creasing ridges 140 also help to prevent movementbetween the template 136 and the sponge sheet 116 during cutting.

The templates 108, 124, 136 may be separate members included in apuncture closure kit including the introducer and pusher or may be fixedto one of the members of the puncture closure system. For example, thetemplate may be attached to a staging chamber of the introducer 12.

FIGS. 21 through 24 illustrate vent caps for assisting in hydrating andstaging pledgets within the delivery devices of the present invention.The vent caps provide the ability to more rapidly hydrate the pledgetand provide the ability to locate the pledget at a desired axiallocation within the delivery device.

One preferred embodiment of a vent cap 144 for use on the distal end ofthe introducer 12 is shown in FIG. 21. The vent cap 144 is received overthe distal end of the introducer 12, as shown in FIG. 22, with a rim 146of the cap forming a friction fit with an exterior surface of theintroducer. The vent cap 144 includes an interior dome 148 having a venthole 150. Although the vent hole 150 has been illustrated in a center ofthe dome 148, the vent hole may be located at other positions or may beprovided between the vent cap 144 and the distal end of the introducer12. The vent hole 150 allows the operator to apply high pressures withthe syringe to the interior of the introducer 12 and allows air andfluid to exit through the vent hole. This high pressure can be used todrive the pledget 40 to the distal end of the introducer and to drivefluid into the pledget causing very rapid hydration of the pledgetmaterial. High pressure is intended to mean pressures of about 5 psi orgreater. The interior dome 148 allows a distal end of the pledget 40 tobe positioned just distal of the distal end of the introducer 12. Thevent cap 144 can be removed and the introducer 12 is then inserted overthe proximal end of the guidewire and advanced to the puncture site. Thepledget material extending from the distal end of the introducer 12provides a rounded surface for assisting in passing the introducerthrough the layers of tissue to the blood vessel puncture site.

The shape of the interior dome 148 of the vent cap 144 may be modifiedto achieve different positions of the distal end of the pledget withrespect to the distal end of the introducer 12. For example, if thepledget is to be contained completely within the introducer 12, aninverted dome, cone, or cylinder shaped vent cap may be used in whichthe dome, cone, or cylinder extends partially into the distal lumen ofthe introducer 12. Alternatively, if the pledget is to be positioned atthe distal end of the introducer 12, the interior of the vent cap may beflat.

FIG. 23 illustrates an alternative embodiment of a vent cap 156 which isparticularly configured for use with the separate staging chamber 170 ofthe introducer shown in FIG. 29. The vent cap 156 preferably includes aluer fitting 158 which is attachable to a distal end of the stagingchamber 170. The vent cap 156 includes a finger 160 which extends to orinto a distal end of the staging chamber 170. The finger 160 has acentral vent 162. The use of the vent cap 156 with the finger 160 allowsthe pledget 40 to be held within the large diameter portion of thestaging chamber 170 for quick and easy hydration of the pledget. Thevent finger 160 functions to hold the pledget 40 within the largediameter portion of the staging chamber 170 while injection of fluid bythe syringe is utilized to begin to hydrate the pledget and remove airfrom the staging chamber. The partially hydrated pledget moves forwardto block the vent 162. If the vent 162 has not been entirely blocked bythe pledget, the venturi effect will help draw the pledget toward thevent. Once the vent 162 is blocked, high pressure can be used to drivefluid into the pledget, causing very rapid hydration or super hydrationof the pledget material. Although the vent 162 has been illustrated inthe center of the finger 160, the vent may be located at other positionsor may be provided between the vent cap 156 and the staging chamber 170.

For a delivery system employing the introducer 12 as illustrated in FIG.1, a vent cap similar to that illustrated in FIG. 23 with an elongatedfinger 160 may be used. The elongated finger extends all the way to thestaging chamber 34 to hold the pledget 40 within the staging chamberduring hydration. After hydration of the pledget 40 within the stagingchamber 34, the vent cap with the elongated vent finger is removed andthe pledget is advanced into the delivery chamber.

According to an alternative embodiment, a cap without a vent can be usedfor hydration. The ventless cap acts as a plug to allow hydration byforcing fluid into the introducer which is oriented in a downwarddirection. Air displaced from the pledget and introducer escapes upwardinto the syringe during hydration. In addition, two of the vent caps canbe connected in a single member when used with the same system.

FIG. 25 illustrates an alternative embodiment of a pusher 164 having aproximal stop 166 and a sliding luer 168 or other sliding fitting. Theproximal stop 166 is provided proximal to an enlarged diameter distalportion 172 of the pusher 164. The sliding luer 168 is provided with anaxial through hole having a diameter which is greater than a diameter ofa proximal shaft 174 of the pusher 164 and smaller than the diameter ofthe proximal stop 166. The sliding luer 168 or other sliding fitting isconfigured to be attached to a proximal end of the introducer 12 or of adelivery chamber portion of a two part introducer. Once the sliding luer168 has been attached to the introducer, the proximal movement of thepusher shaft 174 relative to the introducer is limited by the proximalstop 166 abutting the distal face of the sliding luer 168. Thisconfiguration of the pusher 164 is illustrated most clearly in FIG. 27in which the pusher is illustrated as it is used with the introducer 12.The pusher 164 is illustrated in FIG. 27 prior to connection of thesliding luer 168 to the mating luer 42 on the introducer 12. When themating luer 42 is locked to the sliding luer 168, the pledget 40 isconfined between the distal end of the pusher 164 and the vent cap 144which has been used to stage the pledget. Once the vent cap 144 isremoved, the system is ready for delivery of the pledget 40 by advancingthe system including the introducer 12 and the pusher 164 over aguidewire to the target site. Because the proximal movement of thepusher 164 is preset by the proximal stop 166, the pledget 40 cannot bedisplaced proximally during advancement over the guidewire. The pusher164 also includes a proximal luer 176 which can be attached to thesliding luer 168 after delivery of the pledget 40. The introducer andpusher system can then be used to apply pressure to the pledget forlocal compression until hemostasis is achieved.

The proximal stop 166 has been described as formed by an enlargeddiameter portion of the pusher 164. However, the proximal stop may alsobe provided by a disk or other protruding member on the pusher shaft orby a detent and corresponding projection.

According to an alternative embodiment of the invention, the functionsof the sliding luer 168 and proximal stop 166 can be achieved with otherfeatures. For example, one or more detents, reliefs, or ratchet teethprovided on the pusher shaft may engage corresponding features on theintroducer to locate the pusher at a desired position and preventproximal movement of the pusher. FIGS. 28a-f illustrate examples ofthese systems.

FIGS. 28a and 28 b illustrate an alternative embodiment of an adjustableproximal stop employing a ratchet mechanism. As shown in FIG. 28a, theintroducer 12 includes one or more tabs 210 which engage ratchet teeth212 on the pusher 14 to limit proximal motion of the pusher afterinsertion. This system improves deployment control by allowing thepusher position to be maintained at any point during deployment. Theratchet teeth 212 extend along at least a portion of the shaft of thepusher 14. One or more ratchet tabs 210 interact with the teeth 212 ofthe pusher, as shown most clearly in FIG. 28b.

FIG. 28a illustrates the use of the ratchet system to position thepusher 14 adjacent the proximal end of the pledget 40 and trap thepledget between the pusher and the vent cap 144 in preparation for use.Thus, the ratchet teeth 212 allow the system to accommodate pledgets 40of varying sizes. The ratchet system can also provide for partialdeployment of the pledget 40 while continuing to provide resistance toproximal motion of the pusher 14. This can be beneficial for example,for guidewire removal and/or system advancement with the pledget 40 in apartially deployed state.

Although the ratchet tabs 210 have been illustrated on the introducer 12and the ratchet teeth 212 have been illustrated on the pusher 14, theseelements may also be reversed. The ratchet teeth and tabs may also beprovided on other portions of the system that interact, such as handles,luers, locks, or the sliding luer illustrated in FIG. 25.

FIGS. 28c-f illustrate systems having other features for resistance toaxial sliding of the pusher 14. As shown in FIG. 28c, the introducer 12is provided with one or more detents 214. The constant diameter pusher14 d of FIG. 28d is engaged by the detent 214 and provides a frictionfit.

FIGS. 28e and 28 f show alternative embodiments of pushers 14 e, 14 fhaving features which snap over the detent 214. These features includethe grooves 216 and the proximal stop 218. The detent 214 canadvantageously provide tactile feedback of pusher location to the user.As with the embodiment of FIG. 28a employing ratchet teeth and tabs, thedetent 214 and corresponding features may be located on different partsof the system.

FIG. 26 illustrates one preferred embodiment of the distal end of thepusher 164 having an interior funnel 178 for ease in loading the pusherover a guidewire. As a proximal end of the guidewire is advanced intothe pusher 164, the distal funnel 178 guides the guidewire smoothly intothe lumen of the pusher. The distal funnel 178 provides a particularadvantage for facilitating blind loading of the pusher 164 over aguidewire when the pusher is already positioned within the introducer 12or another delivery system.

Although the relative motion of the pusher 14 and the introducer 12 hasbeen described as provided manually, this motion may also be provided byan automatic or spring loaded actuation mechanism.

FIGS. 29-32 illustrate one preferred delivery system according thepresent invention in which the introducer is a two part introducerincluding a separate staging chamber 170 and a delivery chamber 180. Theentire delivery system of FIG. 29 preferably includes the stagingchamber 170, the delivery chamber 180, the pusher 164, and one or morevent caps for the staging and/or delivery chambers such as thoseillustrated in FIGS. 21 and 23. According to this embodiment, thestaging chamber 170 is used with the vent cap 156 of FIG. 23 and asyringe for hydration of the pledget 40 within the staging chamber. Thevent cap 156 is then removed from the staging chamber 170 and thestaging chamber is connected to the delivery chamber as illustrated inFIG. 30. The pledget 40 is advanced from the staging chamber 170 to thedelivery chamber 180 by attaching a syringe to a luer fitting 184 at theproximal end of the staging chamber and providing the vent cap 144 onthe distal end of the delivery chamber 180. With this assembly, thehydrated pledget is advanced to the distal end of the delivery chamber180. The staging chamber 170 is then removed from the delivery chamber180 in preparation for pledget delivery.

As shown in FIG. 31, the pusher 164 is inserted into the deliverychamber 180, the sliding luer 168 is fixed to a distal luer 186 of thedelivery chamber, and the vent cap 144 is removed. This system is usedas previously described to deliver the pledget 40 over a guidewire to adelivery site.

FIG. 32 illustrates the delivery system of FIG. 31 after the pledget 40has been delivered by relative movement between the pusher 164 and thedelivery chamber 180. As shown in FIG. 32, the proximal luer 176 of thepusher 164 is engaged with the sliding luer 168 and the system may beused to apply pressure in the direction of the arrow P to provide localcompression and promote hemostasis. The delivery system employingseparate staging and delivery chambers 170, 180 provides the advantageof a shorter delivery system which can be handled more easily and usedwith shorter guidewires.

The two component introducer system also allows components to be mixedand matched. For example, one staging chamber 170 maybe used withmultiple delivery chambers 180 of different sizes. In addition, thestaging and delivery chambers can be formed of different materials fortheir different material properties. For example, it may be desirable tohave a transparent plastic staging chamber 170 so that the user can viewthe pledget within the staging chamber and determine when the pledgethas been completely hydrated. It may also be desirable to have adelivery chamber 180 formed of stainless steel or other opaque materialwhich is strong, relatively thin, and less expensive to manufacture.FIGS. 33 and 34 illustrate alternative embodiments of dilators havingdistal ends with dilator strain relief features. Conventional dilatorshave distal ends with relatively blunt or spherical shapes and havingdilator lumens which extend through the length of the dilator and aresized to accomodate a guidewire. When these dilators are advanced intoan access tract, the leading blunt or rounded edge of the dilator oftenencounters tissue layers within the subtutaneous tissue that requiresubstantial force to advance the dilator through these layers. Adifficult tissue layer may yield both axially and laterally under theload applied by the dilator. Lateral movement of the dilator can causesignificant deflection of the guidewire and often results in a kinkedguidewire. This increases the challenge of properly introducing thedilator into the tissue tract.

FIG. 33 illustrates a dilator 190 having a flexible distal extension 192with a diameter which is much smaller than an outer diameter of thedilator. For example, the dilator 190 may have a diameter of about 3 to5 mm while the extension 192 has a diameter of about 1 to 2 mm. Thesmall diameter flexible distal extension 192 helps to guide theguidewire into the dilator 190 and reduces the stress concentration onthe guidewire when difficult tissue layers are encountered.

Another alternative embodiment of a dilator 196 is illustrated in FIG.34 in which a funnel shaped lumen 198 at a distal end of the dilatorprovides a guidewire strain relief feature. The enlarged distal opening200 of the dilator 196 allows some guidewire deflection to occur withoutkinking the guidewire as the dilator is advanced over the guidewire. Thefunnel shaped lumen 198 also allows easier passage of kinked guidewires.

Among other advantages, the absorbable sponge delivery system accordingto the present invention permits the delivery of more absorbable spongematerial down a smaller tract by hydrating and compressing theabsorbable sponge material. The over the wire delivery method ensuresthat the absorbable sponge pledget 40 is delivered directly over thepuncture site and remains in the proper position while hemostasis isachieved. The vessel depth indicator system ensures that the absorbablesponge material is positioned adjacent the exterior of the blood vesseland does not extend into the blood vessel to possibly induce thrombosis.The kneading of the absorbable sponge material during rolling of the drysponge and while hydrated and passing through the introducer improvesthe expansion properties of the sponge material.

The absorbable sponge material can be absorbed by the body in a periodof time between several days and several months depending on theabsorbable sponge material used. A pledget 40 formed of commerciallyavailable Gelfoam material will be absorbed by the body within 1 to 6weeks. However, the pledget material may be engineered to providedifferent rates of absorption. For example, Gelfoam can be designed tobe absorbed at different rates by varying the degree of cross-linking.Preferably, the pledget 40 is designed to be absorbed in less than onemonth.

Although the invention is primarily intended for delivery of absorbablesponge, non-absorbable sponge may also be delivered with the devices,systems, and methods of the present invention. A non-absorbable spongemay be desirable where it will be necessary to locate the blood vesselpuncture after the procedure.

Although the pledget 40 has been described as formed from a rectangularshaped piece of an absorbable sponge material which is rolled into acylindrical shape, the pledget may also be formed in different shapesand rolled from different shaped sheets. For example, the pledget 40 maybe preformed in a variety of cross sections including circular,rectangular, star, or other multi-sided shape. The pledget 40 may have afolded cross section and may have through or blind holes formed in thedry pledget. In addition, the pledget size and shape can be matched tothe size and shape of a particular delivery site.

While an amorphous or discontinuous sponge structure may be used in thepresent invention, a continuous structure of the delivered absorbablesponge pledget 40 provides more secure and reliable placement of a plugof material against the blood vessel puncture than a paste or liquid.The continuous sponge structure can even facilitate partial withdrawal,removal, or movement of the ejected pledget.

In accordance with one aspect of the invention, the absorbable spongematerial can be hydrated with a clotting agent such as thrombin, acontrast agent, another beneficial agent, a combination of agents, orthe like. Alternatively, the pledget material itself may contain anagent such as a clotting agent, a contrast agent, another beneficialagent, a combination of agents, or the like.

The absorbable sponge pledget 40 may be presoaked with a beneficialagent such as thrombin for delivery of the beneficial agent to thepunctured blood vessel. Alternatively, the pledget 40 may be hydratedwith a beneficial liquid agent used as the hydrating fluid within thesyringe 50. Further, the beneficial agent may be delivered to thepledget 40 after the pledget is ejected at the blood vessel puncturesite through the lumen of the pusher 14 or through the introducer 12.

The treatment of a blood vessel puncture with a hydrated and injectedpledget 40 of absorbable sponge to facilitate hemostasis providessubstantial advantages in comfort over external pressure methods. Inaddition, the present invention also provides advantages over theinsertion of an absorbable sponge material in a dry state or injectionof a liquid or paste. In particular, the hydration and manipulation or“kneading” of the hydrated Gelfoam pledget 40 as it is passed throughthe introducer 12 improves the expansion and absorption characteristicsof the Gelfoam. The injected Gelfoam conforms in shape quickly to theshape of the puncture site and immediately begins blocking blood flowthrough the puncture site and providing local compression. In contrast,a dry piece of sponge material does not swell until the blood hassufficiently saturated the sponge material, which can take up to hours.The hydrated and kneaded sponge material will expand to a larger sizemuch more quickly when wetted than a piece of dry sponge material whenwetted.

Because the amount of subcutaneous fat and tissue between the skin 106and the blood vessel 102 varies between patients from approximately 0.5cm to 15 cm or more the system may be provided in different lengths foruse in different patients. The pledget 40 size and shape may also bevaried for different patients. The absorbable sponge material shouldform a complete plug over the puncture site without expanding into theblood vessel or exiting the skin of the patient. In some instances wherethe amount of subcutaneous tissue is great it may be desirable todeliver multiple pledgets 40 in spaced apart positions along the tractleading to the puncture site.

The particular size and shape of the introducer 12 may vary depending onthe size of the access site, amount of subcutaneous tissue, and the sizeof pledget 40 to be delivered. According to one example of the presentinvention, a pledget 40 is formed from a rectangular piece ofpre-compressed Gelfoam approximately 2 by 3 cm with a thickness of 0.15cm. The Gelfoam is rolled or folded into a pledget having a length ofapproximately 3 cm. An introducer 12 for delivery of this pledget to apatient with an average amount of subcutaneous tissue has a stagingchamber length of about 2.5 to 6 cm, preferably approximately 3 cm, astaging chamber inner diameter of about 0.12 to 1.5 cm, preferablyapproximately 0.4 cm, and a delivery chamber 36 which is typicallylonger than the staging chamber and has an inner diameter smaller thanthat of the staging chamber of about 1 cm or less, preferablyapproximately 0.33 cm or less. The particular length of the deliverychamber 36 depends on both the subcutaneous tissue depth of the patientand the linear expansion of the pledget 40 as it moves from the stagingchamber 34 to the delivery chamber. An angle made by a wall of thetapered section 38 with a longitudinal axis of the adaptor 12 may varyfrom about 5° to 90°, but is preferably between about 30° and 60°, morepreferably approximately 45°. The tapered section 38 is illustrated witha substantially planar interior surface, when shown in cross section.However, the tapered section 38 may also have a convex or concavesurface in cross-section. This example of pledget 40 and introducer 12configurations is merely exemplary of the present invention.

In accordance with an alternative embodiment of the invention, thepledget 40 may be provided with a rapidly dissolvable tip extending froma distal end of the pledget. Examples of rapidly absorbable ordissolvable tip materials include water-soluble, biocompatible,non-toxic, and preferably non-immunogenic polymers such as poly vinylalcohol (PVA) and ploy vinyl pyrrolidone (PVP). Other examples couldinclude gelatin derived from porcine or bovine sources. Still otherpossible tip materials could include, but are not limited to, polylactic-glycolic acid, poly(proline), ploy(ethylene oxide) andcarbowaxes, methyl cellulose, carboxymethyl cellulose, poly(acrylicacid), poly(hydroxyethyl methacrylate), poly(acrylamide), natural plantgums, and poly(methyl vinyl ether-maleic anhydride).

FIGS. 35 and 36 illustrate a pledget 40 a with a rapidly dissolvable tip200. The rapidly dissolvable tip 200 is arranged to extend slightly intothe blood vessel 102 and will provide an additional locating mechanismwhich will hold the pledget at the proper position over the punctureafter the guidewire is removed as shown in FIG. 36. Preferably, the tip200 extends from the end of the pledget a length not shorter than onewall thickness of the target vessel and not exceeding one wall thicknessplus the lumen diameter of the target vessel. Dissolution rates arepreferably sufficient to facilitate complete absorption of the rapidlydissolvable tip in the lumen within time periods as short as one minuteand not exceeding 72 hours. Preferably, the pledget with the dissolvabletip can also be inserted without the use of the guidewire 26 and thedissolvable tip can serve the locating function of the guidewire foraccurately positioning the pledget over the blood vessel puncture.

The rapidly dissolvable tip 200 may be formed from a thin walled tubewhich extends from an end of the pledget. For example, the thin walledtube may be rolled within the pledget. The guidewire may be threadedthrough the thin walled tube of the dissolvable locating tip or alongone side the locating tip.

As an alternative to the dissolvable tip 200, the locating tip may beformed of a non-dissolvable material and may be removable. For example,the removable tip material may extend through the pledget and all theway to the skin surface. The tip may be withdrawn after a predeterminedtime when the locating function of the tip is no longer needed.

While the invention has been described in detail with reference to thepreferred embodiments thereof, it will be apparent to one skilled in theart that various changes and modifications can be made and equivalentsemployed, without departing from the present invention.

What is claimed is:
 1. A method of super hydrating an absorbable spongematerial for delivery to a body for facilitating hemostasis, the methodcomprising: placing a dry piece of absorbable sponge in a deliverydevice; and subjecting the absorbable sponge to a fluid to rapidly andcompletely hydrate the absorbable sponge in the delivery device, whereinthe fluid is at about 5 psi or greater.
 2. The method according to claim1, wherein the absorbable sponge is provided with a clotting agent. 3.The method according to claim 1, wherein the fluid used for hydratingthe absorbable sponge includes a therapeutic agent.
 4. The methodaccording to claim 1, wherein the fluid used for hydrating theabsorbable sponge includes a clotting agent.
 5. The method according toclaim 1, wherein the delivery device is tubular, and the dry piece ofabsorbable sponge in the delivery device is subjected to the fluid, anddelivered from the tubular delivery device in a hydrated state.
 6. Themethod according to claim 5, wherein the hydrated piece of absorbablesponge is delivered to the body by a pusher.
 7. The method according toclaim 1, wherein the fluid is injected into the delivery device.
 8. Themethod according to claim 7, wherein the fluid is injected into thedelivery device by connecting a syringe to a first end of the deliverydevice.
 9. The method according to claim 8, wherein a vent cap is placedon a second end of the delivery device while the fluid is injected intothe delivery device.
 10. A method of super hydrating an absorbablesponge material for delivery to a body, the method comprising subjectingthe absorbable sponge to a fluid to hydrate the absorbable sponge,wherein the fluid is at about 5 psi or greater.
 11. The method accordingto claim 10, wherein the absorbable sponge is placed in a deliverydevice and the fluid is injected into the delivery device.
 12. Themethod according to claim 10, wherein the hydrated absorbable sponge isdelivered to a body for facilitating hemostasis.
 13. The methodaccording to claim 10, further comprising a step of piercing thehydrated sponge with a delivery device.
 14. A method of super hydratingan absorbable sponge material for delivery to a body, the methodcomprising: placing a dry piece of absorbable sponge in a deliverydevice; and subjecting the absorbable sponge to a fluid to rapidly andcompletely hydrate the absorbable sponge in the delivery device, whereinthe fluid is at about 5 psi or greater.
 15. The method according toclaim 14, wherein the fluid is injected into the delivery device.
 16. Amethod of super hydrating an absorbable sponge material for delivery toa body for facilitating hemostasis, the method comprising: placing a drypiece of absorbable sponge in a delivery device; and subjecting theabsorbable sponge to a fluid to rapidly and completely hydrate theabsorbable sponge wherein the delivery device is placed in a pressurizedcontainer of fluid.
 17. A method of super hydrating an absorbable spongematerial for delivery to a body for facilitating hemostasis, the methodcomprising: placing a dry piece of absorbable sponge in a deliverydevice; and subjecting the absorbable sponge to a fluid to rapidly andcompletely hydrate the absorbable sponge in the delivery device, whereinthe dry piece of absorbable sponge is rolled up prior to placing thesponge in the delivery device.
 18. A method of super hydrating anabsorbable sponge material for delivery to a body for facilitatinghemostasis, the method comprising: placing a dry piece of absorbablesponge in a delivery device; and subjecting the absorbable sponge to afluid to rapidly and completely hydrate the absorbable sponge in thedelivery device, wherein the delivery device has a tapered lumen.
 19. Amethod of super hydrating an absorbable sponge material for delivery toa body for facilitating hemostasis, the method comprising: placing a drypiece of absorbable sponge in a delivery device; and subjecting theabsorbable sponge to a fluid to rapidly and completely hydrate theabsorbable sponge in the delivery device, wherein the fluid used forhydrating the absorbable sponge is a sterile saline solution.
 20. Amethod of super hydrating an absorbable sponge material for delivery toa body for facilitating hemostasis, the method comprising: placing a drypiece of absorbable sponge in a delivery device; and subjecting theabsorbable sponge to a fluid to rapidly and completely hydrate theabsorbable sponge in the delivery device, wherein the absorbable spongeis provided with a contrast agent to facilitate visualization.
 21. Amethod of super hydrating an absorbable sponge material for delivery toa body for facilitating hemostasis, the method comprising: placing a drypiece of absorbable sponge in a delivery device; and subjecting theabsorbable sponge to a fluid to rapidly and completely hydrate theabsorbable sponge in the delivery device, wherein the fluid used forhydrating the absorbable sponge includes a contrast agent to facilitatevisualization.